1. Field of the Invention
This disclosure relates to an image formation apparatus.
2. Description of Related Art
Among conventional image formation apparatuses such as printers, copiers, facsimiles, and multifunction printers, there is a printer, for example, which performs printing on long paper as a medium on which black marks are arranged at equal pitches in the medium's lengthwise direction. This type of printer is configured to set a print start position at which the printing starts on a paper conveyance route when a black mark sensor provided to a main body of the printer, i.e., an apparatus main body detects a black mark before the printing starts. A print unit starts the printing when a predetermined point of the paper arrives at the print start position.
Further, the printer is provided with a cutter unit at a predetermined position upstream of the print unit on the paper conveyance route. The printer with the cutter unit is configured to set a cut position that indicates where to cut the paper on the paper conveyance route when the black mark sensor detects a black mark after completion of the predetermined printing. The printer with the cutter unit is further configured to stop and cut the paper at the cut position by means of the cutter unit when a predetermined point of the paper arrives at the cut position.
However, this type of printer may fail to detect a black mark at the appropriate timing if a conveyance roller or the like of a conveyance unit for conveying the paper slips, or if a paper jam occurs.
When a black mark is not detected, the paper is stopped, and an operator of the printer is notified that the black mark is not detected, i.e., is notified of the occurrence of a black-mark detection error (see, for example, Japanese Patent Application Publication No. 2012-91437).
Meanwhile, there has also been provided a printer configured to make a paper slack between the print unit and the cut position on the paper conveyance route. This type of printer has no need to stop the paper at the cut position for the purpose of cutting the paper. Therefore, the print unit can stably perform the printing (see, for example, Japanese Patent Application Publication No. H1-231745).